OSLD nanoDot characterization for carbon radiotherapy dosimetry
This study characterized OSLD nanoDots for use in a therapeutic carbon beam using the IROC framework for remote output verification. 
Approach: The absorbed dose correction factors for OSLD (fading, linearity, beam quality, angularity, and depletion), as defined by AAPM TG 191, were characterized for carbon beams. For the various correction factors, the effect of carbon LET was examined by characterizing in both a low and high LET setting. 
Main Results: Fading was not statistically different between reference photons and carbon, nor between low and high LET carbon; thus, the standard IROC-defined exponenti...
Source: Physics in Medicine and Biology - April 25, 2024 Category: Physics Authors: Paige Taylor Shannon Hartzell Alfredo Mirandola Mario Ciocca Giuseppe Magro Paola Alvarez Christine B Peterson Christopher R Peeler Eugene J Koay Rebecca M Howell Stephen F Kry Source Type: research
Inter-scanner super-resolution of 3D cine MRI using a transfer-learning network for MRgRT
In this study, we present a personalized super-resolution (psSR) network that incorporates transfer-learning to overcome the challenges in inter-scanner SR of 3D cine MRI.
Approach: Development of the proposed psSR network comprises two-stages: 1) a cohort-specific SR (csSR) network using clinical patient datasets, and 2) a psSR network using transfer-learning to target datasets. The csSR network was developed by training on breath-hold and respiratory-gated high-resolution (HR) 3D MRIs and their k-space down-sampled LR MRIs from 53 thoracoabdominal patients scanned at 1.5 T. The psSR network was developed through ...
Source: Physics in Medicine and Biology - April 25, 2024 Category: Physics Authors: Younghun Yoon Jaehee Chun Kendall Kiser Shanti Marasini Austen Nathaniel Curcuru H Michael Gach Jin Sung Kim Taeho Kim Source Type: research
An end-to-end multi-scale airway segmentation framework based on pulmonary CT image
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad4300. Online ahead of print.ABSTRACTOBJECTIVE: Automatic and accurate airway segmentation is necessary for lung disease diagnosis. The complex tree-like structures leads to gaps in the different generations of the airway tree, and thus airway segmentation is also considered to be a multi-scale problem. In recent years, convolutional neural networks have facilitated the development of medical image segmentation. In particular, 2D CNNs and 3D CNNs can extract different scale features. Hence, we propose a two-stage and 2D+3D framework for multi-scale airway tree segmentatio...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Ye Yuan Wenjun Tan Lisheng Xu Nan Bao Quan Zhu Zhe Wang Ruoyu Wang Source Type: research
Spread-out Bragg peak measurements using a compact quality assurance range calorimeter at the Clatterbridge Cancer Centre
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad42fd. Online ahead of print.ABSTRACTOBJECTIVE: The superior dose conformity provided by proton therapy relative to conventional X-ray radiotherapy necessitates more rigorous Quality Assurance (QA) procedures to ensure optimal patient safety. Practically however, time-constraints prevent comprehensive measurements to be made of the proton range in water: a key parameter in ensuring accurate treatment delivery.APPROACH: A novel scintillator-based device for fast, accurate water-equivalent proton range QA measurements for ocular proton therapy is presented. Experiments were...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Saad Shaikh Sonia Escribano-Rodriguez Raffaella Radogna Laurent Kelleter Connor Godden Matthew Warren Derek Attree Ruben Saakyan Linda Mortimer Peter Corlett Alison Warry Andrew Gosling Colin Baker Andrew Poynter Andrzej Kacperek Simon Jolly Source Type: research
GMAlignNet: multi-scale lightweight brain tumor image segmentation with enhanced semantic information consistency
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad4301. Online ahead of print.ABSTRACTAlthough the U-shaped architecture, represented by UNet, has become a major network model for brain tumor segmentation, the repeated convolution and sampling operations can easily lead to the loss of crucial information. Additionally, directly fusing features from different levels without distinction can easily result in feature misalignment, affecting segmentation accuracy. On the other hand, traditional convolutional blocks used for feature extraction cannot capture the abundant multi-scale information present in brain tumor images. ...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Jianli Song Xiaoqi Lu Yu Gu Source Type: research
TOPAS simulation of photoneutrons in radiotherapy: accuracy and speed with variance reduction
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad4303. Online ahead of print.ABSTRACTWe provide optimal particle split numbers for speeding up TOPAS Monte Carlo simulations of linear accelerator (linac) treatment heads while maintaining accuracy. In addition, we provide a new TOPAS physics module for simulating photoneutron production and transport. 
TOPAS simulation of a Siemens Oncor linac was used to determine the optimal number of splits for directional bremsstrahlung splitting as a function of the field size for 6MV and 18MV x-ray beams. The linac simulation was validated against published data of lateral ...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Jose Asuncion Ramos-Mendez Ramon Ortiz Jan Schuemann Harald Paganetti Bruce A Faddegon Source Type: research
Meeting the detector challenges for pre-clinical proton and ion computed tomography
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad42fc. Online ahead of print.ABSTRACTSix decades after its conception, proton computed tomography (pCT) and proton radiography have yet to be used in medical clinics. 
However, good progress has been made on relevant detector technologies in the past two decades, and a few prototype pCT systems now exist that approach the performance needed for a clinical device.
The tracking and energy-measurement technologies in common use are described, as are the few pCT scanners that are in routine operation at this time.
Most of these devices still look like ...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Robert P Johnson Source Type: research
Performance evaluation of the FastIC readout ASIC with emphasis on Cherenkov emission in TOF-PET
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad42fe. Online ahead of print.ABSTRACTThe efficient usage of prompt photons like Cherenkov emission is of great interest for the design of the next generation, cost-effective, and ultrahigh-sensitivity TOF-PET scanners. With custom, high power consuming, readout electronics and fast digitization the prospect of sub-300 ps FWHM with PET-sized BGO crystals have been shown. However, these results are not scalable to a full system consisting of thousands of detector elements.
Approach. To pave the way toward a full TOF-PET scanner, we examine the performance of the Fas...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Markus Piller Antonio M Castilla Giulia Terragni Jerome Alozy Etiennette Auffray Rafael Ballabriga Michael Campbell Bernd Deutschmann David Gascon Alberto Gola Stefano Merzi Alicja Michalowska-Forsyth Michele Penna Sergio G ómez Fernández Nicolaus Krato Source Type: research
Prompt gamma timing for proton range verification with TlBr and TlCl as pure Cherenkov emitters
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad4304. Online ahead of print.ABSTRACTObjective.Prompt gamma timing (PGT) uses the detection time of prompt gammas emitted along the proton track in proton radiotherapy to verify Bragg peak positioning. Cherenkov detectors offer the possibility of enhanced signal-to-noise ratio (SNR) due to Cherenkov physics which enhances detection of high energy prompt gamma rays relative to other induced uncorrelated signals. In this work, the PGT technique was applied to 3 semiconductor materials that emit only Cherenkov light: a 3x3x20 mm3TlBr, a 12x12x12 mm3TlBr, and a 5x5x5 mm3 TlCl...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Justin Ellin Leonor Rebolo Michael Backfish Eric Prebys Gerard Ari ño-Estrada Source Type: research
Probabilistic U-Net model observer for the DDC method in CT scan protocol optimization
Phys Med Biol. 2024 Apr 24. doi: 10.1088/1361-6560/ad4302. Online ahead of print.ABSTRACTOptimizing complex imaging procedures within Computed Tomography,
considering both dose and image quality, presents significant challenges amidst rapid
technological advancements and the adoption of Machine Learning (ML) methods.
A crucial metric in this context is the Difference-Detailed Curve, which relies on
human observer studies. However, these studies are labor-intensive and prone to
both inter- and intra-observer variability. To tackle these issues, a ML-based model
observer utiliz...
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: David Stocker Christian Sommer Sarah Gueng Jason St äuble Ismail Özden Jennifer Griessinger Mathias Weyland Gerd Lutters Stephan Scheidegger Source Type: research
Deep-learning model for background parenchymal enhancement classification in contrast-enhanced mammography
Conclusion: The proposed BPE classification tool for CEM achieves similar results than
what is published in the literature for CE-MRI.PMID:38657641 | DOI:10.1088/1361-6560/ad42ff (Source: Physics in Medicine and Biology)
Source: Physics in Medicine and Biology - April 24, 2024 Category: Physics Authors: Elodie Ripaud Cl ément Jailin Gonzalo Inaki Quintana Pablo Milioni Ruben Sanchez de la Rosa Laurence Vancamberg Source Type: research
A scan-specific quality control acquisition for clinical whole-body (WB) MRI protocols
Phys Med Biol. 2024 Apr 22. doi: 10.1088/1361-6560/ad4195. Online ahead of print.ABSTRACTImage quality in whole-body MRI (WB-MRI) may be degraded by faulty radiofrequency (RF) coil elements or mispositioning of the coil arrays. Phantom-based quality control (QC) is used to identify broken RF coil elements but the frequency of these acquisitions is limited by scanner and staff availability. This work aimed to develop a scan-specific QC acquisition and processing pipeline to detect broken RF coil elements, which is sufficiently rapid to be added to the clinical WB-MRI protocol. The purpose of this is to improve the quality o...
Source: Physics in Medicine and Biology - April 22, 2024 Category: Physics Authors: Sam Keaveney Georgina Hopkinson Julia E Markus Andrew N Priest Erica Scurr Julie Hughes Scott Robertson Simon J Doran David J Collins Christina Messiou Dow-Mu Koh Jessica M Winfield Source Type: research
Patient-specific temperature distribution prediction in laser interstitial thermal therapy: single-irradiation data-driven method
Phys Med Biol. 2024 Apr 22. doi: 10.1088/1361-6560/ad4194. Online ahead of print.ABSTRACTLaser interstitial thermal therapy (LITT) has been popular for treating brain tumours and epilepsy. The strict control of tissue thermal damage extent is crucial for LITT. Temperature prediction is useful for predicting thermal damage extent. Accurately predicting in vivo brain tissue temperature is challenging due to the temperature dependence and the individual variations in tissue properties. Considering these factors is essential for improving the temperature prediction accuracy.OBJECTIVE: To present a method for predicting patient...
Source: Physics in Medicine and Biology - April 22, 2024 Category: Physics Authors: Tingting Gao Libin Liang Hui Ding Guangzhi Wang Source Type: research
TIST-Net: style transfer in dynamic contrast enhanced MRI using spatial and temporal information
In this study, our objective is to develop a style transfer method that incorporates spatio-temporal information to either add or remove contrast enhancement from an existing image.
 
We propose a Temporal Image-to-Image Style Transfer Network (TIST-Net), consisting of an auto-encoder combined with convolutional long short-term memory (LSTM) networks. This enables disentanglement of the content and style latent spaces of the time series data, using spatio-temporal information to learn and predict key structures . To generate new images , we use deformable and adaptive convolutions which allow fine grained c...
Source: Physics in Medicine and Biology - April 22, 2024 Category: Physics Authors: Adam George Tattersall Keith A Goatman Lucy E Kershaw Scott I K Semple Sonia Dahdouh Source Type: research
Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps
Phys Med Biol. 2024 Apr 22. doi: 10.1088/1361-6560/ad4192. Online ahead of print.ABSTRACTSpatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a...
Source: Physics in Medicine and Biology - April 22, 2024 Category: Physics Authors: Yolanda Prezado Michael Grams Emmanuel Jouglar Immaculada Martinez-Rovira Ramon Ortiz Joao Seco Sha Chang Source Type: research
